Commercial production of many durable products, for example, automotive, aerospace, industrial, and appliances, etc, involve manufacturing methods which include hot forging, extrusion, cutting, etc. Forging and extrusion dies must be very robust in order to have an adequate service life. Dies are generally heat treated in order to obtain sufficient hardness to resist distortion during use in manufacturing processes. However, the hardness obtained by heat treating decreases with time as high temperature work pieces repeatedly come in contact with the die surface. Decreased hardness results in changes in the dimensions of the die due to deformation. Thus, the die must be replaced.
Some die materials have poor resistance to oxidation therefore build up surface oxide scale which alters the die cavity dimensions.
In cutting tool applications, hardened tools can lose their edge and/or performance due to softening which results from heating of the cutting edge by friction during contact with work pieces.